Electric lighting accounts for approximately 40 percent of all energy consumed in modern buildings. It has long been recognized that incorporating available daylight can reduce these annual energy costs by 40 to 50 percent using “daylight harvesting” techniques. The basic principle of daylight harvesting is to monitor the amount of daylight entering an interior space and dim the electric lighting as required to maintain a comfortable luminous environment for the occupants. Where required, motorized blinds and electrochromic windows may also be employed to limit the amount of daylight entering the occupied spaces. Further energy savings can be realized through the use of occupancy sensors and personal lighting controls that operate in concert with the daylight harvesting system and are therefore considered integral thereto.